1. Field of the Invention
The present invention relates to a display device, and more particularly, to an organic light emitting diode (OLED) display device and a method of driving the same.
2. Discussion of the Related Art
With the advancement of information-oriented society, various requirements for display field are increasing, and thus, research is being done on various flat panel display devices that are thin and light, and have low power consumption. For example, the flat panel display devices are classified into liquid crystal display (LCD) devices, plasma display panel (PDP) devices, OLED display devices, etc.
Especially, OLED display devices that are being actively studied recently apply data voltage (Vdata) having various levels to respective pixels to display different grayscale levels, thereby realizing an image.
To this end, each of a plurality of pixels includes one or more capacitors, an OLED, and a driving transistor that are current control elements, wherein, a current flowing in the OLED is controlled by the driving transistor, and the amount of the current flowing in the OLED are changed by a threshold voltage deviation of the driving transistor and various parameters, causing the non-uniformity of a screen luminance.
The threshold voltage deviation of the driving transistor occurs because the characteristic of the driving transistor is changed due to a variable manufacturing process used for the driving transistor. To overcome this limitation, each pixel generally includes a compensation circuit that includes a plurality of transistors and capacitors for compensating for the threshold voltage deviation.
Recently, as consumers' requirements for high definition increase, a demand for a high-resolution OLED display device has increased. To this end, it is necessary to integrate more pixels into a unit area for high resolution, and thus, it is required to reduce the numbers of transistors, capacitors, and lines included in the compensation circuit that compensates for a threshold voltage deviation.